Learning to Learn: Real-Time Features and a Connectionist Model

Abstract

Two experiments used classical conditioning to examine transfer of response features specific to the warning interval between a conditioned stimulus (CS) and an unconditioned stimulus (US). Rabbits were given initial training with a stimulus (CSA) in one modality (tone) at a designated interval (e.g., 200 ms). In a second stage, the conditioned response (CR) to CSA was extinguished. Finally, training was shifted to a new stimulus (CSB) in another modality (light) at a new interval (e.g., 400 ms). Compared to rest controls, there was an enhanced rate of CR acquisition to CSB and a tendency for early CRs to CSB to reflect the CSA-US interval. However, the extinction procedure and the change in CS-US interval together reduced these two aspects of transfer across stimulus modalities. The findings are discussed in terms of their implications for theories of cross-modal transfer. A layered network with real-time features is offered.